source: branches/samba-3.5.x/source3/lib/sharesec.c

Last change on this file was 414, checked in by Herwig Bauernfeind, 15 years ago

Samba 3.5.0: Initial import
File size: 10.1 KB
Line 
1/*
2 * Unix SMB/Netbios implementation.
3 * SEC_DESC handling functions
4 * Copyright (C) Jeremy R. Allison 1995-2003.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 3 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include "includes.h"
21
22/*******************************************************************
23 Create the share security tdb.
24 ********************************************************************/
25
26static struct db_context *share_db; /* used for share security descriptors */
27#define SHARE_DATABASE_VERSION_V1 1
28#define SHARE_DATABASE_VERSION_V2 2 /* version id in little endian. */
29
30/* Map generic permissions to file object specific permissions */
31
32extern const struct generic_mapping file_generic_mapping;
33
34static int delete_fn(struct db_record *rec, void *priv)
35{
36 rec->delete_rec(rec);
37 return 0;
38}
39
40bool share_info_db_init(void)
41{
42 const char *vstring = "INFO/version";
43 int32 vers_id;
44
45 if (share_db != NULL) {
46 return True;
47 }
48
49 share_db = db_open(NULL, state_path("share_info.tdb"), 0,
50 TDB_DEFAULT, O_RDWR|O_CREAT, 0600);
51 if (share_db == NULL) {
52 DEBUG(0,("Failed to open share info database %s (%s)\n",
53 state_path("share_info.tdb"), strerror(errno) ));
54 return False;
55 }
56
57 vers_id = dbwrap_fetch_int32(share_db, vstring);
58 if (vers_id == SHARE_DATABASE_VERSION_V2) {
59 return true;
60 }
61
62 if (share_db->transaction_start(share_db) != 0) {
63 DEBUG(0, ("transaction_start failed\n"));
64 TALLOC_FREE(share_db);
65 return false;
66 }
67
68 vers_id = dbwrap_fetch_int32(share_db, vstring);
69 if (vers_id == SHARE_DATABASE_VERSION_V2) {
70 /*
71 * Race condition
72 */
73 if (share_db->transaction_cancel(share_db)) {
74 smb_panic("transaction_cancel failed");
75 }
76 return true;
77 }
78
79 /* Cope with byte-reversed older versions of the db. */
80 if ((vers_id == SHARE_DATABASE_VERSION_V1) || (IREV(vers_id) == SHARE_DATABASE_VERSION_V1)) {
81 /* Written on a bigendian machine with old fetch_int code. Save as le. */
82
83 if (dbwrap_store_int32(share_db, vstring,
84 SHARE_DATABASE_VERSION_V2) != 0) {
85 DEBUG(0, ("dbwrap_store_int32 failed\n"));
86 goto cancel;
87 }
88 vers_id = SHARE_DATABASE_VERSION_V2;
89 }
90
91 if (vers_id != SHARE_DATABASE_VERSION_V2) {
92 int ret;
93 ret = share_db->traverse(share_db, delete_fn, NULL);
94 if (ret < 0) {
95 DEBUG(0, ("traverse failed\n"));
96 goto cancel;
97 }
98 if (dbwrap_store_int32(share_db, vstring,
99 SHARE_DATABASE_VERSION_V2) != 0) {
100 DEBUG(0, ("dbwrap_store_int32 failed\n"));
101 goto cancel;
102 }
103 }
104
105 if (share_db->transaction_commit(share_db) != 0) {
106 DEBUG(0, ("transaction_commit failed\n"));
107 return false;
108 }
109
110 return true;
111
112 cancel:
113 if (share_db->transaction_cancel(share_db)) {
114 smb_panic("transaction_cancel failed");
115 }
116
117 return false;
118}
119
120/*******************************************************************
121 Fake up a Everyone, default access as a default.
122 def_access is a GENERIC_XXX access mode.
123 ********************************************************************/
124
125SEC_DESC *get_share_security_default( TALLOC_CTX *ctx, size_t *psize, uint32 def_access)
126{
127 uint32_t sa;
128 SEC_ACE ace;
129 SEC_ACL *psa = NULL;
130 SEC_DESC *psd = NULL;
131 uint32 spec_access = def_access;
132
133 se_map_generic(&spec_access, &file_generic_mapping);
134
135 sa = (def_access | spec_access );
136 init_sec_ace(&ace, &global_sid_World, SEC_ACE_TYPE_ACCESS_ALLOWED, sa, 0);
137
138 if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, 1, &ace)) != NULL) {
139 psd = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1,
140 SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL,
141 psa, psize);
142 }
143
144 if (!psd) {
145 DEBUG(0,("get_share_security: Failed to make SEC_DESC.\n"));
146 return NULL;
147 }
148
149 return psd;
150}
151
152/*******************************************************************
153 Pull a security descriptor from the share tdb.
154 ********************************************************************/
155
156SEC_DESC *get_share_security( TALLOC_CTX *ctx, const char *servicename,
157 size_t *psize)
158{
159 char *key;
160 SEC_DESC *psd = NULL;
161 TDB_DATA data;
162 NTSTATUS status;
163
164 if (!share_info_db_init()) {
165 return NULL;
166 }
167
168 if (!(key = talloc_asprintf(ctx, "SECDESC/%s", servicename))) {
169 DEBUG(0, ("talloc_asprintf failed\n"));
170 return NULL;
171 }
172
173 data = dbwrap_fetch_bystring(share_db, talloc_tos(), key);
174
175 TALLOC_FREE(key);
176
177 if (data.dptr == NULL) {
178 return get_share_security_default(ctx, psize,
179 GENERIC_ALL_ACCESS);
180 }
181
182 status = unmarshall_sec_desc(ctx, data.dptr, data.dsize, &psd);
183
184 TALLOC_FREE(data.dptr);
185
186 if (!NT_STATUS_IS_OK(status)) {
187 DEBUG(0, ("unmarshall_sec_desc failed: %s\n",
188 nt_errstr(status)));
189 return NULL;
190 }
191
192 if (psd)
193 *psize = ndr_size_security_descriptor(psd, NULL, 0);
194
195 return psd;
196}
197
198/*******************************************************************
199 Store a security descriptor in the share db.
200 ********************************************************************/
201
202bool set_share_security(const char *share_name, SEC_DESC *psd)
203{
204 TALLOC_CTX *frame;
205 char *key;
206 bool ret = False;
207 TDB_DATA blob;
208 NTSTATUS status;
209
210 if (!share_info_db_init()) {
211 return False;
212 }
213
214 frame = talloc_stackframe();
215
216 status = marshall_sec_desc(frame, psd, &blob.dptr, &blob.dsize);
217
218 if (!NT_STATUS_IS_OK(status)) {
219 DEBUG(0, ("marshall_sec_desc failed: %s\n",
220 nt_errstr(status)));
221 goto out;
222 }
223
224 if (!(key = talloc_asprintf(frame, "SECDESC/%s", share_name))) {
225 DEBUG(0, ("talloc_asprintf failed\n"));
226 goto out;
227 }
228
229 status = dbwrap_trans_store(share_db, string_term_tdb_data(key), blob,
230 TDB_REPLACE);
231 if (!NT_STATUS_IS_OK(status)) {
232 DEBUG(1, ("set_share_security: Failed to store secdesc for "
233 "%s: %s\n", share_name, nt_errstr(status)));
234 goto out;
235 }
236
237 DEBUG(5,("set_share_security: stored secdesc for %s\n", share_name ));
238 ret = True;
239
240 out:
241 TALLOC_FREE(frame);
242 return ret;
243}
244
245/*******************************************************************
246 Delete a security descriptor.
247********************************************************************/
248
249bool delete_share_security(const char *servicename)
250{
251 TDB_DATA kbuf;
252 char *key;
253 NTSTATUS status;
254
255 if (!share_info_db_init()) {
256 return False;
257 }
258
259 if (!(key = talloc_asprintf(talloc_tos(), "SECDESC/%s",
260 servicename))) {
261 return False;
262 }
263 kbuf = string_term_tdb_data(key);
264
265 status = dbwrap_trans_delete(share_db, kbuf);
266 if (!NT_STATUS_IS_OK(status)) {
267 DEBUG(0, ("delete_share_security: Failed to delete entry for "
268 "share %s: %s\n", servicename, nt_errstr(status)));
269 return False;
270 }
271
272 return True;
273}
274
275/*******************************************************************
276 Can this user access with share with the required permissions ?
277********************************************************************/
278
279bool share_access_check(const NT_USER_TOKEN *token, const char *sharename,
280 uint32 desired_access)
281{
282 uint32 granted;
283 NTSTATUS status;
284 SEC_DESC *psd = NULL;
285 size_t sd_size;
286
287 psd = get_share_security(talloc_tos(), sharename, &sd_size);
288
289 if (!psd) {
290 return True;
291 }
292
293 status = se_access_check(psd, token, desired_access, &granted);
294
295 TALLOC_FREE(psd);
296
297 return NT_STATUS_IS_OK(status);
298}
299
300/***************************************************************************
301 Parse the contents of an acl string from a usershare file.
302***************************************************************************/
303
304bool parse_usershare_acl(TALLOC_CTX *ctx, const char *acl_str, SEC_DESC **ppsd)
305{
306 size_t s_size = 0;
307 const char *pacl = acl_str;
308 int num_aces = 0;
309 SEC_ACE *ace_list = NULL;
310 SEC_ACL *psa = NULL;
311 SEC_DESC *psd = NULL;
312 size_t sd_size = 0;
313 int i;
314
315 *ppsd = NULL;
316
317 /* If the acl string is blank return "Everyone:R" */
318 if (!*acl_str) {
319 SEC_DESC *default_psd = get_share_security_default(ctx, &s_size, GENERIC_READ_ACCESS);
320 if (!default_psd) {
321 return False;
322 }
323 *ppsd = default_psd;
324 return True;
325 }
326
327 num_aces = 1;
328
329 /* Add the number of ',' characters to get the number of aces. */
330 num_aces += count_chars(pacl,',');
331
332 ace_list = TALLOC_ARRAY(ctx, SEC_ACE, num_aces);
333 if (!ace_list) {
334 return False;
335 }
336
337 for (i = 0; i < num_aces; i++) {
338 uint32_t sa;
339 uint32 g_access;
340 uint32 s_access;
341 DOM_SID sid;
342 char *sidstr;
343 enum security_ace_type type = SEC_ACE_TYPE_ACCESS_ALLOWED;
344
345 if (!next_token_talloc(ctx, &pacl, &sidstr, ":")) {
346 DEBUG(0,("parse_usershare_acl: malformed usershare acl looking "
347 "for ':' in string '%s'\n", pacl));
348 return False;
349 }
350
351 if (!string_to_sid(&sid, sidstr)) {
352 DEBUG(0,("parse_usershare_acl: failed to convert %s to sid.\n",
353 sidstr ));
354 return False;
355 }
356
357 switch (*pacl) {
358 case 'F': /* Full Control, ie. R+W */
359 case 'f': /* Full Control, ie. R+W */
360 s_access = g_access = GENERIC_ALL_ACCESS;
361 break;
362 case 'R': /* Read only. */
363 case 'r': /* Read only. */
364 s_access = g_access = GENERIC_READ_ACCESS;
365 break;
366 case 'D': /* Deny all to this SID. */
367 case 'd': /* Deny all to this SID. */
368 type = SEC_ACE_TYPE_ACCESS_DENIED;
369 s_access = g_access = GENERIC_ALL_ACCESS;
370 break;
371 default:
372 DEBUG(0,("parse_usershare_acl: unknown acl type at %s.\n",
373 pacl ));
374 return False;
375 }
376
377 pacl++;
378 if (*pacl && *pacl != ',') {
379 DEBUG(0,("parse_usershare_acl: bad acl string at %s.\n",
380 pacl ));
381 return False;
382 }
383 pacl++; /* Go past any ',' */
384
385 se_map_generic(&s_access, &file_generic_mapping);
386 sa = (g_access | s_access);
387 init_sec_ace(&ace_list[i], &sid, type, sa, 0);
388 }
389
390 if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, num_aces, ace_list)) != NULL) {
391 psd = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1,
392 SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL,
393 psa, &sd_size);
394 }
395
396 if (!psd) {
397 DEBUG(0,("parse_usershare_acl: Failed to make SEC_DESC.\n"));
398 return False;
399 }
400
401 *ppsd = psd;
402 return True;
403}
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